No abstract

Background: The germline telomerase reverse transcriptase (TERT) rs2736100_C variant was identified as a susceptibility factor for a variety of solid tumors and recently for myeloproliferative neoplasms (MPN).Methods: LightCycler melting curve analysis was applied to detect risk alleles of TERT rs2736100_C and Janus kinase 2 (JAK2) rs12343867_C tagging 46/1 haplotype in 584 BCR-ABL1-negative MPN, 308 acute, and 86 chronic myeloid leukemia (AML and CML) patients and 400 healthy individuals.Results: TERT rs2736100_C showed an increased allele frequency in BCR-ABL1-negative MPN patients compared with controls (62.7%AE2.8% vs. 48.8%AE3.5%, P < 0.0001) regardless of molecular background or disease type, but not in CML or AML. Combined TERT and JAK2 hetero-or homozygosity conferred even higher risk for classic MPN. Common complications (throm-

Internal tandem duplications (ITDs) of the fms-like tyrosine kinase 3 (FLT3) gene occur in about 25% of patients with adult acute myeloid leukemia (AML). The aim of our study was to investigate the frequency of FLT3-ITD mutations followed by a detailed analysis of the mutational load and size of ITD insertions in a cohort consisting of 324 patients younger than 60 years old and treated with curative intention. FLT3-ITD alone did not influence overall survival (OS) or disease-free survival (DFS). We observed worse OS and DFS for patients with high mutational load indicative for loss of the FLT3 wild type allele (p = 0.010, p = 0.038, respectively). In multivariate analyses, patients with FLT3-ITD(48-60bp) showed worse OS and DFS compared to other groups (FLT3-ITD(neg), FLT3-ITD (< 48b), FLT3-ITD (> 60bp); p = 0.014, p = 0.019, respectively). Our novel observation suggested that not only high FLT3-ITD load, but also medium-sized ITD insertions (48-60 bp) represented an adverse prognostic subgroup of patients with AML.

No abstract

Bevezetés: A Philadelphia-kromoszóma negatív, "klasszikus" myeloproliferativ neoplasiák genetikai hátterében a Janus kináz 2, a calreticulin-és a trombopoetinreceptor génmutációit azonosították. Célkitűzés: A kóroki mutáció azonosí-tása 949, myeloproliferativ neoplasiában szenvedő betegnél. Módszer: A szerzők minőségi és mennyiségi allélspecifi -kus polimeráz láncreakció, fragmensanalízis, nagy felbontású olvadásigörbe-analízis és Sanger-szekvenálás kombiná-cióit alkalmazták. Eredmények: 354 polycytaemia verában szenvedő beteg 98,6%-a (n = 349) hordozta a Janus kináz 2 gén V617F mutációját, 1,4%-uk (n = 5) pedig a 12. exon mutációit. Esszenciális thrombocythaemiában (n = 468) a betegek 61,3%-ánál (n = 287) V617F-, 25,2%-ánál (n = 118) calreticulin-és 2,1%-ánál (n = 10) trombopoetinreceptor-génmutációt találtak, míg a betegek 11,3%-a (n = 53) a fenti mutációk egyikét sem hordozta (triplán negatí-vak). Hasonló eloszlást tapasztaltak primer myelofi brosisban (n = 127): 58,3% (n = 74) V617F-, 23,6% (n = 30) calreticulin-, 6,3% (n = 8) trombopoetinreceptor mutáció pozitív, 11,8% (n = 15) triplán negatív. Következtetések: A calreticulingént érintő, nemrégiben felfedezett mutációk révén a Philadelphia kromoszóma negatív, "klasszikus" myeloproliferativ neoplasiában szenvedő betegek közel 90%-ánál határozható meg a betegséget okozó genetikai eltérés. Orv. Hetil., 2014, 155(52), 2074-2081 Kulcsszavak: polycytaemia vera, esszenciális thrombocythaemia, primer myelofi brosis, Janus kináz 2, calreticulin Complex molecular genetic diagnostic algorithm in the diagnosis of myeloproliferative neoplasmsIntroduction: Mutations in Janus kinase 2, calreticulin and thrombopoietin receptor genes have been identifi ed in the genetic background of Philadelphia chromosome negative, "classic" myeloproliferative neoplasms. Aim: The aim of the authors was to identify driver mutations in a large myeloproliferative cohort of 949 patients. Method: A complex array of molecular techniques (qualitative and quantitative allele-specifi c polymerase chain reactions, fragment analyzes, high resolution melting and Sanger sequencing) was applied. Results: All 354 patients with polycythemia vera carried Janus kinase 2 mutations (V617F 98.6%, exon 12: 1.4%). In essential thrombocythemia (n = 468), the frequency of V617F was 61.3% (n = 287), that of calreticulin 25.2% (n = 118), and that of thrombopoietin receptor mutations 2.1% (n = 10), while 11.3% (n = 53) were triple-negative. Similar distribution was observed in primary myelofi brosis (n = 127): 58.3% (n = 74) V617F, 23.6% (n = 30) calreticulin, 6.3% (n = 8) thrombopoietin receptor mutation positive and 11.8% (n = 15) triple-negative. Conclusions: The recent discovery of calreticulin gene mutations led to defi nite molecular diagnostics in around 90% of clonal myeloproliferative cases.